Safety locking device for manually operated circuit breakers



Dec. 22, 1953 Filed Jan. 9, 1952 C. P. SORENSEN SAFETY LOCKING DEVICE FOR MANUALLY CIRCUIT BREAKERS OPERATED LSheets-Sheet 1 BY a ATTORNEY.

j INVENTOR.

' C RL PSORENSEN Dec. 22, 1953 c. P. SORENSEN 2,663,768 SAFETY LOCKING DEVICE FOR MANUALLY OPERATED CIRCUIT BREAKERS Filed Jan. 9, 1952 2 Sheets-Sheet 2 ATTORNEY Patented Dec. 22, 1953 SAFET LOCKING DEVICE FOR MA'NI- 1A1, EnA'rEn omcorr BREAKERS fi 1 sorensen, Ch a 5 1: Application January 9, 1952, Serial- No. 265,64?

This invention relates broadly to circuit breakers and more particularly to novel locking means for circuit breakers.

In circuit breaker-installations. in general, and particularly in panelbcard' and load center installations, it is often desired or imperative that the setting of aparticular breaker or group of breakers remain undisturbed. Situations often occur in which a breaker or group of breakers have been set in on or on! position with some important purpose in mind, and some unauthorized person either purposefully or inadvertently changes the settings of the breaker or group of breakers. Situations of this nature. may result in annoying interruptions to. service or opera tions, and may even cause serious damage to apparatus and injury tov persons who. may be relying on the setting'of the breaker or group of breakers.

Heretofore certain instances circuit breakers mounted in metal enclosures have been provided with a locking means for locking the breakers in set position. The form of locking means 6011-. sisted of walls formed integral with the cover of the metal box enclosing the breaker and surroundin the slot provided in the cover for the manual operating member. Oppositely disposed openings were provided in the side walls to form staples for receiving the hasp of a padlock. 4

Since it could not be accurately foreseen whether any particular breaker would require a locking means, it was necessary to provide the metal box of each of a line of breakers with the locking means described above.

In panelboard installations involving a plurality of breakers, it has not been .possibleheretoe fore to prevent movement of the operating handle of any particular breaker except by'providing a cover for the entire board and locking'the cover in closed position; Accordingly, the primary ob-. ject of my invention is to provide a novel and an improved form of a device for preventing movemerit of a circuit breaker control ihandlel Another object of myiinventi'on is to provide an improved form of a device for preventing move: ment of the operatin handle-member of a C11": cuit breaker, Which is capable of being quickly and easily attached to or detached from the circuit breaker structure .where said handle has a hole provided therein, or where a hole can be so provided.

Another obieet of my invention is to provide an improved form of 'attachment for preventing movement of the operating handle member of a circuit breaker which-'isadapted for use. With C a ms, (01, 0.01

many types. ofelectrical switches where the handle member has a hole provided therein. where it is possible. to. drill a hole.

Another object or my invention is. o pro 11. a locking device having associated parts. incl ding a locking bar for attachment to a circuit, breaker structure for preventing. substallliiEilv mo ement. of the operating handle member thereofand a padlock for preventing detachment of the d vice. from the breaker structure.

Another object of the invention is. the provision of a portable device ofzunitarystructure for preventing. substantial movement. of the. operating handle member. of a. circuit. breaker, or. any switch, having an opening in the handle. member thereof.

A still further object of my invention is the provision of a device for preventing substantial movement of the operating handle member oi a circuit breaker in which the device is. provided with means'for quick attachment to orv removal from the circuit brea'kerstructure and in which locking means are provided for. preventing. re; moval of the device from the circuit. breaker structure.

A still further object of the. invention isto. provide a device which maybe removably attached to a circuit breaker structure forpre; venting substantial movement of the. operating member thereof and which functionsas an indie; cator to indicate that the setting of the breaker is not to be disturbed.

A still further object of my invention is. to pro: vide a device attachable to a circuit breaker structure for preventing substantial movement of the operating member thereof, which is of simple and rugged construction and which can be manue ii 'ed e $919 a a re at low o ener lly mv'inveei e sie of? u atlas member, or han le. The ham e guard i11 i e were I .191 e the end edge of the rectangular shaped opening aes is Prov de insul r ext nding no can to c n ti s. th d1 1; insecure operatin needle 1 hr rer w n attends outside brearerqasios an o p. vent substantial movement of said l ar; e posi on oi the. b mu euard ma be reversed so that he. perati handle .ofthe breaker be held either in its open or closed circuit position. The operating handle of the breaker is provided with an opening, such as a drilled hole, extending therethrough parallel with its uppermost surface and extending in a direction which is in alignment with the movement of said handle. The angular .or outwardly extending portion of the bumper guard also is provided with an opening, or drilled hole, said hole extending therethrough and in direct alignment with the opening in said handle. A shoulder pin is provided whereby it may be placed with its shoulder in contact with one side of said handle, so that the pin portion thereof will extend through the opening in the handle and then through the opening in the bumper guard with an end portion thereof extending outwardly from said bumper guard. A locking bar is provided with an opening therein through which said end portion of said shoulder pin will extend when said bar is placed over said pin and in contact with the outer surface of the bumper guard. Securing means is provided within said locking bar for rigidly securing said bar to said pin. A locking means is also provided in the form of a lock body and with a pivoted hasp, said hasp shaped to extend through a second opening in said locking bar preventing access to said securing means whereby said pin may not be removed from said bumper guard and said operating handle if it is not so desired.

Other objects and advantages, more or less ancillary to the foregoing and the manner in which all the various objects are realized will appear in the following detailed description and accompanying drawings wherein is assembled and pointed out certain details of structure and aggroupment of parts connotative of the scope of the invention as defined in the appended claims.

Referring to the drawings which illustrate the preferred embodiment of the invention:

Figure 1 is a vertical sectional view of a circuit breaker structure to which this invention can be attached, the circuit breaker being enclosed in a suitable box, the front cover and body of the box being shown in sections;

Figure 2 is a front view of the circuit breaker structure shown in Figure 1; r Figure 3 is a side view of a circuit breaker structureas shown in Figure 1, a portion of the side wall broken away and a portion of the cover shown in section, and said structure having one form of this invention shown attached thereto; the locking bar shown in section;

Figure 4 is a front view of the circuit breaker structure as shown in Figure 3 with one form of this invention shown attached thereto;

Figure 5 is a disassembled perspective view showing one form of this invention, and comprising a locking bar, an allan set screw, an allan wrench, a guard member, a shoulder pin, a padlock, and a key for said padlock;

Figure 6 is an enlarged sectional view showing the locking bar of this invention in section, with an allan wrench inserted in an allan set screw which is in tight contact with the pin surface of 4 structure as long as the manually operating lever has an opening therein.

In Fig. l, the improved form of locking device is shown attached to a circuit breaker. The circuit breaker illustrated in Figures 1, 2, 3 and i is of the same general type as is disclosed in Patents No. 1,802,758 and 2,192,060 for illustrative purposes only. The details of the circuit breaker shown in Fig. 1 are not an essential part of this invention, but are merely shown by way of example. The circuit breaker illustrated in Figures 1, 2, 3 and 4 comprises a base it] to which is secured a cover or casing member II. The casing and base are of suitable material as desired and are formed to provide a chamber 12 in which is mounted the circuit breaker contact means, and the operating means therefor. A stationary contact I5 is mounted on the base at the forward end of the compartment. The stationary contact is electrically connected to a suitable terminal not shown. A movable contact I8 is secured to a contact carrying arm 28 at one end thereof. The other end of the contact carrying arm is secured to a channel shaped contact supporting frame (not shown) which is pivotally mounted between the side walls of a main frame 22 by means of a pin 24. A cradle member 26 is pivotally mounted at one end thereof on a pin 28 carried at the forward end of the main frame between the side walls thereof. Toggle links 30 and 32 interconnect the cradle member with the movable contact carrying frame. A U-shaped operating member 35 has the lower ends of its legs pivotally secured to the side walls of the main frame as indicated at 36. An overcenter spring 38 has one end thereof connected to the knee pivot iii of the toggle linkage 30, and -32, and its other end secured to a lug 44 formed on the underside of the bight portion of said operating member. An operating handle 46 of insulating material is provided with a curved closure portion to which is secured to the top of the bight portion of the operating member. Said handle it has a hole 5G drilled therein parallel with its upper surface. The operating handle extends through an elongated slot 52 of rectangular shape provided in the cover M.

The U-shaped bimetallic trip element 5 5 is com nected to an outside terminal now shown. The other end of the bimetallic trip element is connected through a metallic supporting base 56 for the trip element, and a terminal 58, with a hexible conductor 50. The conductor til is electrically connected to the movable contact carrying arm 20. The upper end of the bimetallic trip element is provided with a latch portion 64 which is adapted to engage and hold a latch nose 3% formed on the free end of the cradle member 2%. An angle piece 10 is secured to the underside of the curved portion of the operating handle st for engaging and moving the cradle member in a counter-clockwise direction about its pivot point 28 to reset the circuit breaker. For aiding in the extinction of the arcs which are formed incident to the opening of the circuit controlled by the breaker, an arc extinguishing device E2 of the spaced plate type is provided. The features of this extinguisher are not an important part of my invention and any suitable structure may be utilized.

The operation of the circuit breaker described above is briefly as follows: The circuit breaker is shown in the tripped position, and the operating handle must be moved to open position to reset the mechanism before the breaker can be closed aeaa'zea from this position. Movement oi theoperati-n handle 46 to engage and move the cradle 26 in a counterclockwise direction to a position in which the latch nose B6 is engaged and held by the latched portion 64' of the bimetallic trip. element. In this position of the parts described, the movable contact is in its open circuit position. If the operating handle 46 is now moved tothe right, to a position in which it is adjacent the edge it of the opening 52 in the casing, the overcenter spring will move the toggle linkage 30' and 32 to an extended position to cause the movable contact to move with a snap action into engagement with the stationary contact l5. Movement oftheoperating handle to its open circuit position in which it is adjacent the edge M of the. opening will cause the overcenter spring to break the toggle linkage 3B and 32. and thus move the movable contact 18 to an open circuit position with a snap action. With the movable'contact |8- in its closed circuit position and the nose 66 of the cradle engaged and held by the bimetallic trip element, if an overload occurs on the circuit in Which the contacts l3 and I5 are connected, the bimetallic trip element 54 will be heated by the overload current and bend in a direction away from the nose $6 of the cradle member to release the same; The release of the cradle member 56 causes the overcenter spring to break the toggle linkage and thus move the contact l8 to an open circuit position. This last operation takes place irrespective of the position of the operating handle 46. The release of the cradle 66 in response to an overload also effects movement of the operating handle 46 to an intermediate indicating position as shown in Fig. 1 to indicate that the breaker has been tripped open.

One form of the locking deviceof the present invention clearly illustrated in Figures 4, 6, and '7 and also more clearly shown in Figure-5 is a disassembled perspective view. Said device consisting of a metallic locking bar 82 having a, 'lateral opening 83 adjacent its end 84 and a lateral opening 85 adjacent its end :86. Said bar also has a transverse opening 88 or circular cross section extending from its end 86 to said lateral opening 83, and passing through lateral opening 85. The section of the circular opening 88 between openings 83 and 85 is provided withinternal threads. An allan set screw 89 with external threads is placed within the threaded section of opening 88-, said screw having its closed end so extending toward said opening 83 and with its end having its key socket extending toward said opening 85. By this arrangement of said parts, one end portion of'an allan wrench 82 can be inserted through the open end of opening 88 and arranged in the key socket of said alla'n set screw 89. As shown in Figure 6, when the pin portion 94 of a shoulder pin 95 is inserted within said lateral opening 83, saidp in 96 can be secured in looking engagement with the wall the. passage way tothefthreaded sectlpn oi the opening 88. It is clearlyshown, in Eigiire, Ft

he. guard member Lilli has a lateral; pertain 11" an. angular p rtion. [02. said. snap at portion to: rovided withan openin 0.31. A. k y L05. is also. Shawn in said figure 1;. s d. kev t0. b used, with said lock. 85 in the. usual" manner-.

The locking device describe "above. may e attached tothje. br.cake.r"structure. in he; following. manner.. The end 95; oi. shoulder p n. 95; may b inserted through opening 50. from the, underside;

of said opening 83 by screwing the end portion of the operating handle 4'6 and through opening we of. guard-memb r um. if properly placed wi its-lateralportion [M within'the opening. 52 0i cover-l4 and withits angular portio 102 against the. u per surface/H of. hand e. 45.. The and 9.5. or said. pin s4. will extend. beyondthe. exposed. surface H1! or guard U10.- The locking. bar 82. may be placed. upon said pin, portion-1,4 by allowing the end portion. 1501. said pinto extend ei-itirely through the opening 83' of sai bar. Th bar as is then forced into. tight en a ement with portion. 102 or said/guard r00. With, the bar 32 in position against'sa'id, guard m9, and. s id. guard loll against said handle 46 the bar can be securely looked upon said pin 9.4,. by urning. said set screw 39. within thethreaded portion of opening. at. until its. end portion. 9!! is in contact wi h said pin 94; this turning action being accomplished by inserting saidallan. Wrench, 92 into the open end of openingflll and arranging. same within the socket of said set sdrew and then turning said wrench. in. a clockwise direction. After said pin 94 is locked Within said bar 82., said alla nv wrench is removed. The operator then unlocks the padlock S8 with. key Hi5 whereby the hasp. 9,8 of said padlock 391s free topivot within said padlock 99. The free end portion :05, of the hasp 93 is then inserted intosaid opening of said bar 82 whereby said free end 106 will extend beyond said bar 82 so that the padlock body portion 99 can be raised into engagement with said hasp and both portions locked together in a secure union due to the usual snap action of the padlock. With the padlock 99 and hasp 98 so arranged it is impossible for anyone to insert an alien wrench 92' into said opening 88 for som tacting said set screw 89 'to turn the same in a counterclockwise direction to remove the bar 82. from said pin 94.

When the locking device is arran ed as do scribed above, theoperati-ng handle cannot b moved any substantial amount. The locking device may be inserted in the opening either in h open. position as shown in Fi ures 1, 3 nd 4 or in a reverse p sition so that th pera in handle may be held against substantial movement in either its closed circuit position or open circuit position, whichever is desired. .t is clearly shown in Figure 1 that the breaker is in tripped condition with movable contact H3 in open position. When the guard is inserted within the slot and locked against the operating handle in either on or off? position, the handle can never be moved a sufficient amount to cause the contacts to be opened or closed.

This novel locking rrieans described above may be used with any standard lines of switches either oi the current responsive or noncurrent responsive types as lon as a hole is inovid d within the operating handle for the insertion of a shoulder pin, or dislike, whereby the insertedpin'can extend through the holewithin the out wardly extending portion ofsaid' guard; said holes seams in said handle and said guard should be substan-' tially in alignment.

Although the foregoing description is necessarily of a detailed character, in order to define the structure, function and advantages of the invention it is to be understood that the specific terminology is not to be restricted or confining and that various arrangements of the parts and alternate combinations of elements may be resorted to without departing from the scope or spirt of the invention as herein claimed.

I claim:

1. The combination with. a circuit interrupter having an oscillatable operating handle movable back and forthin a single plane to on and "01 positions and having a casing provided with a slot in which the operating handle is movable, said handle having an opening therethrough, of a rigid guard removably mountable in said slot in either of two opposite positions for contacting an inclined surface of said operating handle, said guard having an opening therethrough, of a shoulder pin member removably placeable through said openings arranged in said operating handle and said rigid guard, of a locking bar, said locking bar having an opening therethrough to receive one end of said pin member, and a securing means for locking said bar to said pin member.

2. The combination with a circuit interrupter having an oscillatable operating handle movable back and forth in a single plane to on and oii positions and having a casing provided with a slot in which the handle is movable, said handle having an opening therethrough, of a rigid guard removably mountable in said slot in either of two opposite positions for contacting an upwardly inclined surface of said handle, said rigid guard having an opening therethrough, of a member removably placeable through said openings arranged in said handle and said guard, of a looking bar, said locking bar having an opening therethrough, and an adjustable securing means for locking said bar to said member.

3. The combination with a circuit interrupter having an oscillatable operating handle movable back and forth in a single plane to on and an positions and having a casing provided with a slot in which the handle is movable, of a rigid guard removably mountable in said slot in either of two opposite positions for contacting a surface of said handle, said handle and said rigid guard having aligned openings therethrough, of a member removably placeable through said aligned openings arranged in said handle and said guard, of a locking bar, said locking bar having an opening therethrough, and an adjustable securing means for locking said bar to said member.

4. The combination with a circuit interrupter having an oscillatable operating handle movable back and forth in a single plane to on and off positions and having a casing provided with a slot in which the handle is movable, of a rigid guard removably mountable in said slot in either of two opposite positions for contacting an inclined surface of said handle, said handle and said rigid guard having aligned openings therethrough, of a member removably placeable through said aligned openings arranged in said handle and said rigid guard, of a locking bar, said locking bar having an opening therethrough, of an adjustable securing means for locking said bar to said member, and a locking means engageable with said bar for preventing adjustment of said adjustable securing means.

5. The combination with a circuit interrupter having an oscillatable operating handle movable back and forth in a single plane to on and ed positions and having a casing provided with a rectangular slot in which the handle is movable, of a guard removably mountable in said slot in either of two opposite positions for contacting an end portion of said slot and the upper inclined surface of said handle, said handle and said guard having aligned openings with each other therethrough, of a shoulder pin removably placeable through said aligned openings arranged in said handle and said guard, of a locking bar, said locking bar having an opening therethrough, of an adjustable securing means arranged adjacent the opening in said locking bar, said securing means for locking said bar to said shoulder pin, of a second opening within said bar, and a locking means arranged in said second opening within said bar for preventing adjustment of said securing means to unlock said bar upon said member.

6. The combination with a circuit interrupter having an oscillatable operating handle movable back and forth in a single plane to on and off positions and having a casing provided with a rectangular slot in which the handle is movable, of a guard removably mountable in said slot in either of two opposite positions for contacting an end portion of said slot and the upper inclined surface of said handle, said handle and said guard each having aligned openings with each other therethrough, of a shoulder pin removably placeable through said aligned openings arranged in said handle and said guard, of a locking bar, said locking bar having an opening therethrough, of an adjustable securing means arranged adjacent the opening in said locking bar, said securing means for locking said bar to said shoulder pin, of a second opening within said bar, and a locking means provided in the form of a lock body and with a pivoted hasp, said hasp shaped to extend through said second opening in said locking bar preventing access to said securing means whereby said pin may not be removed from said bumper guard and said operating handle when it is not so desired.

7. The combination with a circuit interrupter having an oscillatable operating handle movable back and forth in a single plane to on and oif positions and having a casing provided with a rectangular slot in which the handle is movable, of a guard removably mountable in said slot in either of two opposite positions for contacting the upper inclined surface of said handle, said handle and said guard having aligned openings with each other therethrough, of a shoulder pin removably placeable through said aligned openings arranged in said handle and said guard, of a locking bar, said locking bar having an opening formed adjacent one end thereof, said locking bar having a larger opening formed adjacent the opposite end thereof, said locking bar having a transverse opening therein connecting said openings adjacent each end thereof, of an adjustable allanset screw in said transverse opening and arranged adjacent the smaller of said openings, said allan set screw for locking said bar to said shoulder pin, and of a locking means provided in the form of a lock body and with a pivoted hasp, said hasp shaped to extend through the larger opening at one end of said locking bar preventing access to said securing means whereby said pin may not be removed from said bumper guard and said operating handle when it is not so desired.

8. lfhe combination with a circuit interrupter having an oscillatable operating handle movable back and forth in a single plane to on and 01T positions and having a casing provided with a rectangular slot in which the handle is movable, of a guard removably mountable in said slot in either of two opposite positions for contacting the upper inclined surface of said handle, said handle and said guard having aligned openings therethrough, of a shoulder pin removably placeable through said aligned openings arranged in said handle and said guard, of a locking bar, said locking bar having an opening formed adjacent one end thereof, said locking bar having a larger opening formed adjacent the opposite end thereof, said locking bar having a transverse opening therein connecting said openings adjacent each end thereof, of an adjustable allan set screw in said transverse opening and arranged adjacent the smaller of said openings, said allan set screw for locking said bar to said shoulder pin, said allan set screw adjusted from one position to another by the manipulation of an allan wrench if and when inserted within said transverse opening, and of a locking means provided in the form of a lock body and with a pivoted hasp, said hasp shaped to extend through the larger opening at one end of said locking bar preventing access to said securing means, whereby said pin may not be removed from said bumper guard and said operating handle for unlocking the parts.

9. In a circuit breaker, a casing, contact means, means including a manually operated control handle member movable in an open circuit position and to a closed circuit position for causing corresponding movements of said contact means, said casing having an opening through which said control handle member extends, a guard removably positioned in said opening for contacting an inclined surface of said handle member, said guard and said handle member each having aligned openings therein, a shoulder pin removably placeable through said openings arranged in said guard and said handle member, a locking bar, said locking bar having an opening adjacent one end thereof through which the end of said pin may extend, and an adjustable securing means for locking said bar to said pin for preventing substantial movement of said control handle member while said guard is so positioned.

10. In a circuit breaker, a casing, contact means, means including a manually operated control handle member movable to an open circuit position and to a closed circuit position for causing corresponding movements of said contact means, said casing having a rectangular opening through which said control handle member extends, a guard removably positioned in said rectangular opening for contacting an inclined surface of said handle member, said guard and said handle member each having aligned opening in one end thereof through which the end of said pin may extend, and an adjustable allan set screw in said block for locking said bar to said pin for preventing substantial movement of said control handle member while said guard is so positioned, said guard being of angular formation having a horizontal portion and an upright portion angularly disposed with said horizontal portion.

11. In a circuit breaker,, a casing, contact means, means including a manually operated control member movable to an open circuit position and to a closed circuit position for causing corresponding movements of said contact means, said casing having an opening through which said control member extends, a device removably mounted in said opening to prevent substantial movement of said control member, said device including means for quick attachment to or detachment from the edges of said opening, said device including a guard, a shoulder pin, a looking bar, an allan set screw, andalocking body having a pivoted hasp, said control member having a hole formed therein adjacent its uppermost end, said guard having a hole formed therein adjacent its uppermost end, said pin arranged to be placed through both of said openings and with its shoulder in contact with one side of said control member, said pin also arranged to extend through an opening in said locking bar, said allan set screw being arranged with said locking bar and adjustable so as to contact and secure said bar to said pin, and said locking body arranged whereby the hasp thereof prevents access to said allan screw to prevent adjustment or removal thereof when the parts are not to be unlocked.

12. In a circuit breaker, a casing contact means, means including a manually operated control member movable to an open circuit position and to a closed circuit position for causing corresponding movements of said contact means,

said casing having an opening through which said control member extends, a device removably mounted in said opening to prevent substantial movement of said control member, said device including means for quick attachment to or detachment from the edges of said opening, said device including a guard with a horizontal pa tion and an upwardly extending portion, a shoulder pin, a locking bar means, an allan set screw, and a locking means for preventing detachment of said guard from the edges of said opening.

. CARL P. SORENSEN.

References Cited in the file of this patent UNITED STATES PATENTS Name Date 2,192,060 Wise Feb. 27, 1940 

